Table of Contents
Advertisement
Each byte is separated by an acknowledge (ACK) bit, which the CS42L42 outputs after each input byte is read and is input
to the CS42L42 from the microcontroller after each transmitted byte.
For write operations, the bytes following the MAP byte are written to the CS42L42 register addresses pointed to by the
last received MAP address, plus however many autoincrements have occurred. Note that, while writing, any
autoincrementing block accesses that go past the maximum 0x7F address write to address 0x00—the page address. The
writes then continue to the newly selected page.
0
1
2
3
SCL
CHIP ADDRESS (WRITE)
7
6
5
4
SDA
Addr = 10010
START
Pullup
SDA
Master
Source
For read operations, the contents of the register pointed to by the last received MAP address, plus however many
autoincrements have occurred, are output in the next byte. While reading, any autoincrementing block access that goes
past the maximum 0x7F address wraps around and continues reading from the same page address.
read pattern following the write pattern in
SCL
SDA
START
Pullup
SDA
Source
To generate a read address not based on the last received MAP address, an aborted write operation can be used as a
preamble (see
Fig.
4-50). Here, a write operation is aborted (after the ACK for the MAP byte) by sending a Stop condition.
DS1083F2
Fig. 4-48
4
5
6
7
8
9
10 11
12
MAP BYTE
3
2
1
0
7
6
5
4
ACK
MAP Addr = X
Master
Slave
Figure 4-48. Control-Port Timing, I
Fig.
4-48. Notice how read addresses are based on the MAP byte from
0
1
2
3
4
5
6
CHIP ADDRESS (READ)
7
6
5
4
3
2
1
Addr = 10010
Master
Figure 4-49. Control-Port Timing, I
shows a write pattern with autoincrementing.
13 14 15
16 17 18 19
24 25
DATA
3
2
1
0
7
6
1
0
ACK
Master
Slave
2
C Writes with Autoincrement
7
8
9
16
17
18
DATA
DATA
7
0
7
0
ACK
ACK
Master
Slave
Slave
2
C Reads with Autoincrement
4.16 Control-Port Operation
26
27 28
DATA
DATA
7
6
1
0
7
6
ACK
Master
Master
Slave
Slave
Fig. 4-49
25
27
34
35
36
DATA
0
7
0
NO
ACK
Master
Master Pullup
Slave
CS42L42
1
0
ACK
STOP
Master
Slave
Pullup
shows a
Fig.
4-48.
STOP
85
Advertisement
Table of Contents
Need help?
Do you have a question about the CS42L42 and is the answer not in the manual?